Valve plate component with spring-arm structure

ABSTRACT

The present invention concerns an improved plate component for use in a plate-type non-return valve and comprises a main, outer body portion having at least one integral spring arm extending inwardly therefrom with each said spring arm including at least one curved portion and leading to inner mounting means and in which at least the whole portion of each spring arm lying within an annular region is of reduced thickness relative to the thickness of said main body portion of the component.

United States Patent Brookman Sept. 9, 1975 [54] VALVE PLATE COMPONENT WITH l 385,l47 7/1921 Prellwitz .1 l37/5l6.l3 SPRmG ARM STRUCTURE 2.604196 7/1952 Kehler 137/5"). 1 3 $286,727 ll/l966 Kehler l37/5l6.l3 [75} In n or: n l B m n, l y. England 3,3101166 3/1967 Kchler l37/5l6.l3

[73] Assignee: The Metallic Valve Company Limited, Enghmd Primary ExaminerWilliam R. Cline Armrney, Agent, or FirmSteinberg & Blake [22] Filed: Dec. 11,1973

{21 l rm 423.766 57 ABSTRACT The present invention concerns an improved plate [30] Foreign Application Priority Data component for use in a plate-type non-return valve Dec. [5, 1972 United Kingdom a. 57920/72 and Comprises "min, y Portion having at least one integral spring arm extending inwardly there- [52] U5, Cl 37 51 114 from with each said spring arm including at least one 511 im. c1. 1. Fl6k 15/10; Fl6k 15/12 Curved Portion and leading to inner mounting means [53 Fi ld f S h H 137/515 13 and in which at least the whole portion of each spring arm lying within an annular region is of reduced thick- [56 References Ci ness relative to the thickness of said main body por- UNITED STATES PATENTS of compmen 3()2,U84 4/l9l9 Peters 1. l37/5l6.l3 7 Claims, 1] Drawing Figures PATENTEB 9W5 3.903.921

SHEET 1 [IF 4 VALVE PLATE COMPONENT WITH SPRING-ARM STRUCTURE The present invention relates to an improved plate component for use in plate-type non-return valves such as are used in air compressors and the like machines.

The invention more particularly relates to a valve plate which when assembled in a valve has-frictionless guidance by virtue of the spring or resilient connection of the main body or valve closure portion of the plate to central portion or portions by means of one or more integral spring connecting arms.

A valve plate is known which comprises a main, annular body portion and at least one inwardly extending spring connecting arm integral with the main body portion and merging into a central hub portion. The valve plate is of constant cross section although some plates have been produced with spring connecting arms having discontinuous, hollow-ground portions of restricted length. The plate is secured in the valve housing by clamping the hub together with a guide washer and spring plates between the valve seat and the valve guard.

It has been found in plate-type non-return valves incorporating the known valve plates and particularly with high pressure valves, such as operate in the region of 1000 psi. and have valve plates which are required to be of relatively large thickness, that undesirably high and localised bending stresses are created in the valve plates in the spring arms and in the connecting regions between the arms and the main body portions. Such stresses frequently result in fatigue fractures.

Additionally, undesirable tilting often occurs which produces excessive wear and inefficient operation. in many circumstances, it is highly desirable for the guide regions of the valve plate to be of small dimension and accordingly the length of the spring arm should also be small. However, further disadvantages are created in such a valve plate having short arms since the short arms are consequently more rigid and suffer undesirably high stress effects. Further the lift of such previously mentioned valve plates is reduced by the nature of the resultant relatively inflexible mounting. Still further, where the spring arms of a valve plate are too rigid, considerable difficulty is experienced during assembly in seating the valve plate over its lift washer and furthermore the operating efficiency of the valve is also impaired.

It will accordingly be appreciated that considerable restraints have been imposed on designers of plate type valves and frequently a compromise has had to be made between the desired construction and size and the optimum possible operating characteristics. It should also be noted that inefficient valve operation often occurs as does valve failure because of fatigue fractures resulting from high stress. It will be appreciated that provision of a valve plate having spring arms of increased flexibility and which also minimizes or avoids the other aforementioned disadvantages is highly desirable and of considerable importance.

According to the present invention a plate component for use in a plate-type non-return valve comprises a main, outer body portion having one or more spring arms extending therefrom with the spring arm leading to a common inner portion or to a discrete inner portion and in which at least the portion of each spring arm lying within an annular region and/or substantially the whole length of each spring arm is of reduced thickness relative to the thickness of the main body portion of the component.

Whilst the plate component of the present invention will normally be a valve plate, it is intended that the present invention should include within its scope other plate components, such as damper plates, guide plates and spring plates and having any number of spring arms.

Each spring arm preferably includes at least one curved portion which is usually defined by concentric sides or edges although the spring arm may be of irregular width increasing from a central point to at least one connecting region with the main body.

The transition between the reduced thickness section of each spring arm and the main body portion is preferably a radiussed or slanted surface. The inner portion or portions (hub) may also be of reduced thickness although will normally be of the same thickness as the main body portion and in such latter instance a radiussed or slanting transition surface will be provided between the spring arm and the inner portion. The provision of radiussed or slanting transition surfaces reduces stress concentration and the likelihood of fatigue fractures. The radiussed surfaces should have an as large as possible radius for best effect and the slanting surfaces, when provided, should have a low gradient.

In one embodiment according to the invention a composite plate component is provided and comprises a valve plate having one or more spring connecting arms integral with and projecting from the main body of the plate, and an auxiliary spring member or guide plate having one or more spring or guide arms extending therefrom; the free end of each of said arms of the valve plate having interconnection means and being connected to a free end of the spring arms of the guide plate. At least those portions of the spring arm or arms of the valve plate and/or guide plate lying within an annular region are of reduced thickness. Slanting or radiussed transition surfaces are provided between the reduced thickness portions and the other portions of the component.

It is also intended for the present invention to include within its scope a plate type non-return valve whenever including a valve component as herein described.

it is to be noted that, in operation, the spring arms of i the plate component according to the invention advantageously exhibit improved flexibility and the operation and the versatility of valves including such components is considerably enhanced. Also, localised stressing is advantageously and significantly reduced as a result of the flexing or bending occurring over the whole length of the spring arm. The provision of radiussed or slanting faces further reduces localised stressing. Furthermore, in operation, a more even displacement of the component is advantageously achieved with any tilting effect being minimized or avoided. The tendency for the spring arms to twist is also reduced. The plate component accordingly has improved action and is less likely to sufi'er fatigue fractures.

The reduced thickness of the spring arms or of the spring arms and hub portion may be produced by suitable machining, for example, by means of a grinding wheel or by an electrochemical machining process or by etching. It should be noted that provision of the re duced thickness of at least those portions of the spring arm or arms lying within an annular region, in addition to providing an improved plate component, is also particularly advantageous from a production point of view since when, for example, machining with a grinder, the machining operation is a continuous operation for each plate, and is relatively simple and accordingly economic. The operation can also be readily effected on narrow spring arms such as those having two arcuate portions of different radii. Further a good surface finish is possible with such grinding operation and the valve plate is accordingly improved in such respect.

The invention will be described further, by way of example. with reference to the accompanying drawings, in which:

FIG. I, is a plan view of a simple valve plate having a single spring arm;

FIG. 2 is an enlarged section (not to scale) on the line lI of FIG. 1;

FIG. 3 is a plan view of an alternative embodiment of a valve plate having two spring arms;

FIG. 4 is an enlarged section (not to scale) on the line Illl of FIG. 3. showing the reduced section portions of the spring arms;

FIG. 5, is an enlarged section (not to scale) on the line IIIIII of FIG. I;

FIG. 6 is a section corresponding to that of FIG. 4, but of an alternative embodiment wherein the hub section is also of reduced section;

FIG. 7 is a plan view of a valve plate having three spring arms with each arm having two arcuate portions of differing radii;

FIG. 8 is a plan view of a valve plate which forms one element of a composite plate component, whilst FIG. 8a is a section on the line lV-IV of FIG. 8',

FIG. 9 is a plan view of a guide plate which when connected to the valve plate of FIG. 8, forms said composite plate component; and

FIG. 10 is a partial fragmentary section showing details of the rivetting of the valve plate of FIG. 8, to the guide plate of FIG. 9.

A valve plate I is shown in FIGS. 1 and 2 and comprises a main annular body portion 2. a central hub portion 3 and a single, spring arm 4 of reduced section. The transition surfaces between the spring arm 4 and the hub 3 and between the spring arm 4 and the main body portion 2 are radiussed at 5 and 6 respectively. The hub portion 3 is adapted to be clamped between a valve seat and valve guard (not shown) in known manner.

A locating aperture 7 is provided in the hub 3. A slit 8 separates adjacent portions of the spring arms. Whilst the hub is shown as having the same cross-section as the main body portion, it is also envisaged for the hub also to be of reduced section. In either event, the spring arm lying within an annular region is of reduced section.

In FIGS. 3, 4 and 5 a valve plate is shown comprising a main body portion 11 having arcuate cut-out portions or slots 12 and web portions I3 and the plate is adapted to co-operate with the valve seat of a valve (not shown). The valve plate is initially formed of constant section.

Two spring arms 14, formed integrally with the body portion of the plate, extend from an inner region of the main body portion and extend arcuately therefrom. The spring arms I4 merge into a hub portion which is provided with a locating aperture I7 and which is adapted to be clampingly secured between a valve seat and upper guard in known manner. Suitable cushion and/or spring plates (which may be also constructed in accordance with the invention) and upper and lower lift washers together with loading coil springs or spring plates are provided as necessary.

In FIGS. 3, 4 and 5, it will be seen that the spring arms 14 lying within an annular region are of reduced section and that the transitions between the spring arms I4 and the main body portion 11 of the plate and the central hub portion 15 are radiussed at 16. It will be also seen that the spring arms 14 are of reduced section between the main body portion I1 and hub 15, i.e. along substantially the whole of their length.

In the alternative embodiment illustrated in FIG. 6 the central hub portion I5 is also of reduced section. In this embodiment the central portion 15' will, relative to the previous arrangement, be supported on differently dimensioned or arranged lift washers.

A valve plate is shown in FIG. 7 which comprises a main body portion 18 having slots 19 and web portions 20. Three spring arms 21 of reduced section and having two arcuate portions of differing radii of double curvature extend from the body portion I8 and run into a hub 22. Hub 22 is illustrated as being of the same thickness as the main body portion although may, if desired, be the same reduced section as the spring arms 21. The transition regions between the spring arms 21 and the body 18 and between the spring arms and the hub 22 are radiussed as indicated at 23.

A composite plate component is shown in FIGS. 8 to I0 and comprises a valve plate 24 shown in FIG. 8 and a guide plate 25 shown in FIG. 9. The valve plate comprises main body portion 26, slots 27 and web portions 28. Spring arms 29 of reduced section extend from the main body portion 26 and each terminate in a free interconnecting end 30. The free ends 30 of the arms 29 are apertured and permit interconnection with the guide plate 25 of FIG. 9. FIG. 8a is a section on the line IVIV of FIG. 8 and illustrates the manner in which one of the spring arms 29 is of reduced section and furthermore illustrates the radiussing of the transitional region 41 between the spring arm 29 and the body 24. Similarly, regions 42 (FIG. 8) are also radiussed.

The guide plate 25 comprises a body portion 31 having apertures 32 formed therein. Web portions 33 and 34 have spring arms 35 extending therefrom whilst web portions 36 have arms 37 extending therefrom and merging into hub portion 38 provided for mounting and location purposes. The arms 35 are illustrated as being of the same cross-section as the rest of the guide plate although they may be of reduced section (not shown) with the free ends 35' being preferably although not essentially of the same section as the body 31 of the guide plate. In the latter arrangement the transition regions between the spring arms 35 and the webs of the main body 31 and between the spring arms 35 and the free end portions 35' will be radiussed in the regions 39 lying between adjacent broken lines as indicated in FIG. 9.

FIG. 10 is a partial cross-section through the interconnection region of the composite component formed by interconnection of valve plate 24 with guide plate 25 by means of rivets 40 extending through apertures in the free ends of spring arms 29 and 35.

I claim:

I. A plate component for use in a plate-type now return valve, comprising a main outer body portion having an inner circular periphery, at least one spring arm integral with said outer body portion and extending inwardly from said inner periphery thereof with said spring arm including at least one curved portion terminating in an inner end distant from said inner periphery of said outer body portion, inner mounting means having an outer periphery extending along at least part of a circle which is concentric with and surrounded by said inner circular periphery of said outer body portion, and said peripheries of said outer body portion and inner mounting means respectively extending along circles which define between themselves an annular region separating said inner mounting means and said outer body portion from each other, said inner mounting means being integral with said inner end of said spring arm at said outer periphery of said inner mounting means, and the whole spring arm lying within said annular region and being of reduced thickness relative to the thickness of said main body portion except at a junction with said inner circular periphery thereof where said spring arm has along said inner periphery of said main body portion a transition surface merging into said main body portion at said inner circular periphery thereof.

2. A plate component according to claim 1, wherein said transition surface between said reduced thickness section of spring arm and said main body portion is formed as means to reduce stress concentration.

3. A plate component according to claim 2, in which said inner mounting means is of the same thickness as said main body portion and wherein a transition surface is situated between said spring arm and the inner mounting means along said outer periphery thereof and is formed as a means to reduce stress concentration.

4. A plate component according to claim 2, wherein a plurality of spring arms are provided and lead to said inner mounting means, the latter forming a common, central hub portion.

5. A plate component according to claim 4, wherein each spring arm has at least two curved portions.

6. A plate component according to claim 1, wherein the plate component is a valve plate.

7. A plate component according to claim 1, comprising a valve plate including said main, outer body portion, said spring arm integral therewith, and said inner mounting means integral with said inner end of said spring arm, and a guide plate of substantially the same size and configuration as said valve plate and having also a main outer body portion, at least one spring arm extending therefrom and being integral with an inner periphery thereof and an inner mounting means integral with an inner end of the latter spring arm; said inner mounting means of the valve plate and the guide plate being connected to each other so that said valve plate and guide plate form a composite plate component. 

2. A plate component according to claim 1, wherein said transition surface between said reduced thickness section of spring arm and said main body portion is formed as means to reduce stress concentration.
 3. A plate component according to claim 2, in which said inner mounting means is of the same thickness as said main body portion and wherein a transition surface is situated between said spring arm and the inner mounting means along said outer periphery thereof and is formed as a means to reduce stress concentration.
 4. A plate component according to claim 2, wherein a plurality of spring arms are provided and lead to said inner mounting means, the latter forming a common, central hub portion.
 5. A plate component according to claim 4, wherein each spring arm has at least two curved portions.
 6. A plate component according to claim 1, wherein the plate component is a valve plate.
 7. A plate component according to claim 1, comprising a valve plate including said main, outer body portion, said spring arm integral therewith, and said inner mounting means integral with said inner end of said spring arm, and a guide plate of substantially the same size and configuration as said valve plate and having also a main outer body portion, at least one spring arm extending therefrom and being integral with an inner periphery thereof and an inner mounting means integral with an inner end of the latter spring arm; said inner mounting means of the valve plate and the guide plate being connected to each other so that said valve plate and guide plate form a composite plate component. 